Multiple dural arteriovenous shunts in a 5-year-old boy.
We describe a rare case of multiple dural arteriovenous shunts (DAVSs) in a 5-year-old boy. MR imaging performed at 1 year of age showed only a dilated anterior part of the superior sagittal sinus; however, angiography at 5 years of age revealed an infantile-type DAVS there and two other DAVSs of the adult type. The pathophysiological evolution of DAVSs in children and their treatment strategies are discussed. (+info)
Variant arteriovenous fistula of the superior sagittal sinus--case report.
A 57-year-old male presented with a rare variant of dural arteriovenous fistula, located in the wall of an unobstructed superior sagittal sinus. Drainage occurred through a cortical vein no longer connected to its parent sinus, which filled up a cluster of transmedullary running veins, one of which was the presumed site of hemorrhage. Arterial blood was supplied via the external carotid artery branches. This type of fistula seriously increases the risk of hemorrhage in the patient and therefore requires complete obliteration. Attempts to embolize the fistula failed. The draining vein was isolated and coagulated resulting in permanent occlusion of the fistula. The fistula probably developed through a process of thrombophlebitis and revascularization via arterioles of the vein rather than previous occlusion of the sinus. (+info)
Cavernous sinus and inferior petrosal sinus flow signal on three-dimensional time-of-flight MR angiography.
BACKGROUND AND PURPOSE: Venous flow signal in the cavernous sinus and inferior petrosal sinus has been shown on MR angiograms in patients with carotid cavernous fistula (CCF). We, however, identified flow signal in some patients without symptoms and signs of CCF. This review was performed to determine the frequency of such normal venous flow depiction at MR angiography. METHODS: Twenty-five 3D time-of-flight (TOF) MR angiograms obtained on two different imaging units (scanners A and B) were reviewed with attention to presence of venous flow signal in the cavernous sinus or inferior petrosal sinus or both. Twenty-five additional MR angiograms were reviewed in patients who had also had cerebral arteriography to document absence of CCF where venous MR angiographic signal was detected, as well as to gain insight into venous flow patterns that might contribute to MR angiographic venous flow signal. Differences in scanning technique parameters were reviewed. RESULTS: Nine (36%) of the 25 MR angiograms obtained on scanner A but only one (4%) of the 25 obtained on scanner B showed flow signal in the cavernous or inferior petrosal sinus or both in the absence of signs of CCF. On review of 25 patients who had both MR angiography and arteriography, three patients with venous signal at MR angiography failed to exhibit CCF at arteriography. CONCLUSION: Identification of normal cavernous sinus or inferior petrosal sinus venous signal on 3D TOF MR angiograms may occur frequently, and is probably dependent on technical factors that vary among scanners. The exact factors most responsible, however, were not elucidated by this preliminary review. (+info)
Regions of interest in the venous sinuses as input functions for quantitative PET.
As clinical PET becomes increasingly available, quantitative methods that are feasible in busy clinical settings are becoming necessary. We investigated the use of intracranial blood pools as sources of an input function for quantitative PET. METHODS: We studied 25 patients after the intravenous injection of [18F]6-fluoro-L-m-tyrosine and compared sampled blood time-activity curves with those obtained in small regions of interest (ROIs) defined in the blood pools visible in the PET images. Because of the comparatively large dimensions of the blood pool at the confluence of the superior sagittal, straight and transverse sinuses, a venous ROI input function was chosen for further analysis. We applied simple corrections to the ROI-derived time-activity curves, deriving expressions for partial volume, spillover and partition of tracer between plasma and red blood cells. The results of graphic and compartmental analysis using both sampled [Cs(t)] and ROI [Cr(t)] venous input functions for each patient were compared. We also used an analytic approach to examine possible differences between venous and arterial input functions in the cerebral circulation. RESULTS: Cr(t) peaked significantly earlier and higher than Cs(t) in this patient population, although the total integral under the curves did not differ significantly. We report some apparent differences in the results of modeling using the two input functions; however, neither the graphically determined influx constant, Ki, nor the model parameter that reflects presynaptic dopaminergic metabolism, k3, differed significantly between the two methods. The analytic results suggest that the venous ROI input function may be closer to the arterial supply of radiotracer to the brain than arterialized venous blood, at least in some patient populations. CONCLUSION: We present a simple method of obtaining an input function for PET that is applicable to a wide range of tracers and quantitative methods and is feasible for diagnostic PET imaging. (+info)
Skull metastasis of Ewing's sarcoma--three case reports.
Three cases of skull metastasis of Ewing's sarcoma were treated. The metastatic lesion was located at the midline of the skull above the superior sagittal sinus in all cases. Surgery was performed in two patients with solitary skull lesions involving short segments of the superior sagittal sinus without remarkable systemic metastasis, resulting in good outcome. The third patient had extensive, multiple tumors involving the superior sagittal sinus which could not be excised, and died due to intracranial hypertension. The surgical indication for skull metastasis of Ewing's sarcoma depends on the location and length of the involved superior sagittal sinus, and general condition. (+info)
Absent vestibulo-ocular reflexes and acute supratentorial lesions.
Loss of vestibulo-ocular reflexes occurred in two patients with acute supratentorial lesions who received therapeutic doses of anticonvulsant drugs. There was no clinical or angiographic evidence of focal brain-stem damage. Absence of vestibulo-ocular reflexes is attributed to a combination of acute cerebral damage and anticonvulsant drugs. The loss of these reflexes in patients with acute cerebral lesions cannot be interpreted as evidence of irreversible brain-stem injury. (+info)
Scalp vein detected using internal carotid angiography that did not result in venous sinus compromise.
We present an unusual case of a scalp vein detected by using angiography of the internal carotid artery. The vein arose from the superior sagittal sinus and drained into the deep posterior cervical vein via the parietal emissary vein. This scalp vein may be a collateral pathway for venous sinuses; however, the patient had no evidence of venous sinus occlusive disease or intracranial hypertension. (+info)
Sigmoid sinus thrombosis after mild closed head injury in an infant: diagnosis by magnetic resonance imaging in the acute phase--case report.
Intracranial sinus thrombosis following a mild closed head injury without a skull fracture or intracranial hematoma is extremely rare. A 23-month-old girl presented with vomiting and gait ataxia 1 day after occipital trauma. Computed tomography revealed a slightly increased density area in the region of the left sigmoid sinus. T1-weighted magnetic resonance (MR) imaging demonstrated an isointense area in the left sigmoid sinus and T2-weighted imaging showed a hyperintense area reflecting the characteristics of oxyhemoglobin. MR angiography and cerebral angiography indicated occlusion of the left sigmoid sinus. After 4 days of conservative treatment, her symptoms subsided completely. Follow-up MR angiography and cerebral angiography showed recanalization of the sigmoid sinus. The MR images and MR angiograms were useful for both early diagnosis and follow-up. Treatment should reflect the severity of individual cases, and early diagnosis will help achieve a good outcome. (+info)